Recursion Call Stack – AP CSA

Anatomy of Recursion

Recursion is a method calling itself. Every call pushes a new "Frame" to the computer's memory Call Stack.

Key Requirements

Base Case: A condition that stops the recursive calls (prevents infinite loop & StackOverflowError).

Recursive Step: The part where the method calls itself with a modified parameter moving towards the base case.

LIFO Memory Stack

Last-In, First-Out: The deepest recursive call is the first one to hit the base case and return its value backwards up the stack.